This invention relates to an internal combustion engine whose engine unit support, comprising such sound-generating parts as cylinders, cylinder head, pistons, piston rods, crankschaft bearings, crankshaft, is attached to the crankcase by means of several sound-insulating and force-transmitting elements protecting the crankcase against structure-borne sound and located outside of the oil-wetted area of the crankcase, the axes of these substantially hollow cylindrical sound-insulating elements being parallel to the axis of the crankshaft, and which is provided with a multi-arm bracket, preferably a two-armed lever, at least at the output end of the engine unit support for the purpose of reducing the relative movements of the support to a swinging movement around the crankshaft axis. This lever is attached to the crankshaft bearing seats and provided with at least one sound-insulating element at each end. The bracket arms and the sound-insulating elements are positioned symmetrically to the crankshaft axis, and the position of the sound-insulating elements fastened to the bracket arms relative to the crankcase can be adjusted by means of setting elements in such a way as to make the pre-stressing of the sound-insulating elements completely independent of this position.